This invention relates in general to disposable insulated containers and deals more particularly with a method for making a container blank for use in the manufacture of a disposable insulated container.
In recent years, rapid growth of the fast food industry has created an ever increasing demand for improved disposable insulated containers for serving hot and cold beverages and food products. Containers and cups made from expanded synthetic resin materials such as STYROFOAM, marketed by Dow Chemical Co., Midland, Mich., have enjoyed widespread popularity, because of their excellent thermal insulating characteristics. However, such cups and containers are not biodegradable or recyclable which has caused many communities and municipalities to adopt ordinances prohibiting the dispensing of food products in disposable containers made from such environmentally unfriendly materials. Such action has created an increased demand for improved disposable thermally insulated food containers made from materials which are biodegradable and can be recycled.
Multi-layered thermally insulated paper containers and cups of the type well known in the art have proven to be satisfactory substitutes for containers made from less desirable materials. Such insulated paper containers usually include two or three layers of paper which form the inner and outer sidewall surfaces of the container and define air spaces therebetween. Where three layers of material are employed the inner and outer layers often comprise separate blanks of container stock having a separately formed fluted or corrugated layer sandwiched therebetween. The intermediate layer and the outer layer are usually joined to the inner layer, which forms the inner sidewall of the cup, during the cup making operation. Since the plural layers of material which form the composite sidewall of the insulated cup are usually separately formed and united at the time of cup manufacture a considerable number of material handling operations are often required to bring the materials together which substantially increase the cost of container manufacture. When the cup sidewall is formed by uniting two layers of material to form the cup sidewall the outer layer is usually corrugated or fluted and cooperates with the inner layer to define air space therebetween. Separate operations are usually required to form the inner layer or cup sidewall blank and the fluted or corrugated outer layer. Special machinery may be required to prepare the corrugated or fluted blank which comprises the outer layer of the insulated cup, all of which adds substantially to the cost of cup manufacture.
Accordingly, it is the general aim of the present invention to provide an improved insulated container blank suitable for use in making an insulated cup on a conventional single wrap rotary turret cup making machine of a type well known in the disposable container manufacturing art.